Loss of p16 expression is of prognostic significance in locally advanced prostate cancer: an analysis from the Radiation Therapy Oncology Group protocol 86-10

PURPOSE

The retinoblastoma (RB) cell cycle regulatory pathway is known to be deregulated in virtually all known human tumors. The protein product of the RB gene, pRB, and its upstream regulator, p16, are among the most commonly affected members of this pathway. We investigated the prognostic significance of both pRB and p16 expression in locally advanced prostate cancers, from patients treated on the Radiation Therapy Oncology Group (RTOG) protocol 86-10.

MATERIALS AND METHODS

Sixty-seven cases from RTOG 86-10 had immunohistochemically stained slides, judged interpretable for both p16 and pRB, available for analysis. Median follow-up was 8.9 years (range, 6.0 to 11.8 years) for surviving patients. Staining for each marker was then correlated with overall survival, local progression, distant metastasis, and disease-specific survival.

RESULTS

Loss of p16 expression, as defined by expression was significantly associated with reduced overall survival (P =.039), disease-specific survival (P =.006), and higher risk of local progression (P =.0007) and distant metastasis (P =.026) in the univariate analysis. In the multivariate analysis, loss of p16 was significantly associated with reduced disease-specific survival (P =.0078) and increased risk of local failure (P =.0035) and distant metastasis (P =.026). A borderline association with reduced overall survival (P =.07) was also evident. Loss of pRB was associated with improved disease-specific survival on univariate (P =.028) and multivariate analysis (P =.043), but carried no other significant outcome associations.

CONCLUSION

Loss of p16 is significantly associated with adverse clinical outcome in cases of locally advanced prostate cancer.

Predicting long-term survival, and the need for hormonal therapy: a meta-analysis of RTOG prostate cancer trials

PURPOSE

To assess the impact of short-term and long-term androgen suppression on the disease-specific and overall survival of 2200 men treated with radiotherapy on one of 5 prospective randomized trials when stratified by prognostic risk groups.

METHODS AND MATERIALS

Between 1975 and 1992, 2742 men were treated for clinically localized prostate cancer on one of 5 consecutive prospective Phase III randomized trials. Patients were selected for this analysis if they were deemed evaluable and eligible for the trial, and if follow-up information was available. For this analysis patients were stratified into four previously described prognostic risk groups: Group 1 patients had a Gleason score (GS) = 2-6, and T1-2Nx; Group 2: GS = 2-6, T3Nx; or GS = 2-6, N+, or GS = 7, T1-2Nx; Group 3: T3Nx, GS = 7; or N+, GS = 7, or T1-2Nx, GS = 8-10; and Group 4 patients were T3Nx, GS = 8-10, or N+, GS = 8-10. The median pretreatment prostate-specific antigen (PSA) was 25 ng/ml for the 434 evaluable patients for whom this information was available. The median follow-up times for patients treated on early studies exceeded 11 years, and for more recent studies 6 years.

RESULTS

Risk group 2 patients with "bulky" or T3 disease appeared to have a disease-specific survival benefit at 8 years with the addition of 4 months of goserelin and flutamide. Group 3 and 4 patients were noted to have an approximately 20% higher survival at 8 years with the addition of long-term hormonal therapy (p < or =0.0004).

CONCLUSIONS

Based on this meta-analysis of RTOG trials, subsets of patients can be identified who either do not appear to benefit from the use of hormonal therapy, benefit from short-term hormonal therapy, or who benefit only from long-term hormonal therapy. These observations should be confirmed by prospective randomized trials before they can be considered conclusive. In the meantime, however, these observations provide rational guidelines for deciding who should receive hormonal therapy and for how long.

Common toxicity criteria: version 2.0. an improved reference for grading the acute effects of cancer treatment: impact on radiotherapy

In 1997, the National Cancer Institute (NCI) led an effort to revise and expand the Common Toxicity Criteria (CTC) with the goal of integrating systemic agent, radiation, and surgical criteria into a comprehensive and standardized system. Representatives from the Radiation Therapy Oncology Group (RTOG) participated in this process in an effort to improve acute radiation related criteria and to achieve better clarity and consistency among modalities. CTC v. 2.0 replaces the previous NCI CTC and the RTOG Acute Radiation Morbidity Scoring Criteria and includes more than 260 individual adverse events with more than 100 of these applicable to acute radiation effects. One of the advantages of the revised criteria for radiation oncology is the opportunity to grade acute radiation effects not adequately captured under the previous RTOG system. A pilot study conducted by the RTOG indicated the new criteria are indeed more comprehensive and were preferred by research associates. CTC v. 2.0 represents an improvement in the evaluation and grading of acute toxicity for all modalities.

NCCN urothelial cancer practice guidelines. National Comprehensive Cancer Network

Urothelial tumors represent a spectrum of diseases with a range of prognoses. Once a diagnosis is established at any point on the urothelial tract, the patient remains at risk for developing a new lesion at a different or the same location, at a similar or more advanced stage. Continued monitoring for recurrence is an essential part of management, as most recurrences are superficial and can be managed by endoscopic means. Within each category of disease, more refined methods to determine prognosis and guide management, based on molecular staging, are under development. These methods are aimed at optimizing the individual patient's likelihood of cure and chance for organ preservation. For patients with more extensive disease, newer treatments typically involve combined-modality approaches using recently developed surgical procedures, or three-dimensional treatment planning for more precise delivery of radiation therapy. While these are not appropriate in all cases, they do offer the promise of an improved quality of life and prolonged survival. Finally, within the category of metastatic disease, a number of new agents have been identified that appear to be superior to those currently considered to be standard therapies. It is thought, therefore, that the treatment of urothelial tumors will evolve rapidly over the next few years, with improved outcomes for patients with all stages of disease.

Neoadjuvant combined modality program with selective organ preservation for invasive bladder cancer: results of Radiation Therapy Oncology Group phase II trial 8802

PURPOSE

This phase II study was designed to evaluate effectiveness and toxicity of a combined chemoradiotherapy program with selective bladder preservation in the management of patients with invasive bladder cancer.

PATIENTS AND METHODS

Ninety-one eligible patients with invasive bladder cancer stages T2M0 to T4AM0 suitable for radical cystectomy received two courses of methotrexate, cisplatin, and vinblastine (MCV regimen) followed by radiotherapy with 39.6 Gy and concurrent cisplatin. After complete urologic evaluation, operable patients who achieved complete response were selected for bladder preservation and treated with consolidation cisplatin-radiotherapy.

RESULTS

Of 91 eligible patients, 85 underwent complete urologic evaluation and 68 (75%; 95% confidence interval [CI], 59% to 84%) had documented complete responses. Fourteen operable patients with residual tumor underwent immediate cystectomy. Of 70 patients treated with consolidation cisplatin-radiotherapy, 36 subsequently developed bladder recurrences, 23 of which were invasive. Patients with invasive recurrence (n = 16), extensive noninvasive recurrence (n = 6), or severe treatment complications (n = 1) underwent salvage cystectomy. Thus, a total of 37 of 91 patients (40%) required cystectomy. The 4-year cumulative risk of invasive local failure (which includes induction failures) was 43% (95% CI, 33% to 53%). The 4-year actuarial risk of distant metastasis was 22% (95% CI, 13% to 31%). The 4-year actuarial survival rate of the entire group was 62% (95% CI, 52% to 72%). The 4-year actuarial rate of survival with bladder intact was 44% (95% CI, 34% to 54%).

CONCLUSION

Initial results of this combined chemoradiotherapy program show that bladder preservation can be achieved in the majority of patients, and that overall survival is similar to that reported with aggressive surgical approaches. Long-term survival and quality-of-life assessments require longer follow-up study.

The status of bladder-preserving therapeutic strategies in the management of patients with muscle-invasive bladder cancer

The recommended treatment for medically fit patients with muscle-invading bladder cancer is usually radical cystectomy. However, transurethral resection of the tumor, partial cystectomy, irradiation and systemic chemotherapy are each effective in some patients. These latter treatments allow bladder preservation and cure as an alternative to radical cystectomy although when used unselectively the survival rates are inferior to those of radical cystectomy. The updated results of conservative surgery, radiation therapy and systemic chemotherapy as monotherapy, as well as strategies of combined modality treatment were reviewed. Based on this review many areas of consensus were reached which include: 1. The primary goal of any treatment for a patient with muscle-invading bladder cancer is survival; bladder preservation in the interest of quality of life is a secondary objective. 2. Only a small proportion of carefully selected patients may be cured by transurethral surgery alone, or by partial cystectomy alone. 3. Radiation therapy is currently the standard bladder-preserving therapy against which all other bladder-preserving methods must be compared. 4. Systemic chemotherapy as monotherapy is inadequate and cannot be recommended. 5. The addition of cisplatin-containing systemic chemotherapy to radiation therapy or conservative surgery appears to improve local control. While no multi-modality therapeutic regimen has yet been shown to be clearly optimal with regard to local efficacy and minimizing toxicity, monotherapy for bladder preservation is probably not desirable as a routine approach. 6. Deferring the patient from immediate cystectomy does not appear to compromise survival, nor does the addition of primary systemic chemotherapy appear to significantly increase the morbidity of cystectomy or radiotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Preoperative irradiation for unresectable rectal and rectosigmoid carcinomas

The records of 25 patients with unresectable carcinoma of the rectum and rectosigmoid who received preoperative radiation therapy (RT) were reviewed. Twenty patients were considered to be resectable following RT (80%). Sixteen patients (64%) underwent curative resections. All patients with unresectable tumors following RT died with tumor within two and one half years (median survival, 11 months). For patients undergoing curative resection, the probability of two- and five-year survival was 56% and 43%, respectively. In this latter group, five of seven patients with treatment failures (71%) had a pelvic component of disease. The incidence of pelvic recurrence was correlated with the pathologic stage, extent of resection and preoperative radiation dose. The need for more aggressive treatment for patients with these advanced tumors is emphasized. Future treatment alternatives are discussed.

Evaluation of the clinical applicability of proton beams in definitive fractionated radiation therapy

We report on the treatment of 317 patients treated either wholly or in part with proton beams at the Harvard Cyclotron Laboratory. These include: 130 patients treated for definitive radiation therapy of choroidal melanoma; 17 patients treated for tumors of the base of skull, cervical spine and cranium, which abut structures of the central nervous system (CNS); 23 patients treated for sarcomas of soft tissue and bone; 65 patients treated for carcinoma of the prostate; 14 patients treated for carcinoma of the rectum and anus; and 23 patients treated for squamous carcinoma of the oral cavity and oro-pharynx. Data on causes of failure and morbidity of treatment are presented. Overall the results are judged to be extremely encouraging. In particular, the treatment of the choroidal melanomas and sarcomas abutting CNS structures have clear clinical value, and the treatment of prostatic tumors and tumors of the head and neck are thought to be promising.